1. Field of the Invention
This present invention relates to an acrylic resin film useful for, e.g., surface decoration of a base material and having good matted outer appearances and printing characteristics, a method of producing the same, and a laminate coated with the film on the surface.
2. Description of the Related Art
One of the surface decorating methods which draw a design on a formed article at low cost is in-mold forming. It provides a printed pattern on a sheet or film of, e.g., polyester, polycarbonate or acrylic resin, and injects a resin for the base onto the sheet or film placed in the injection mold, where the sheet or the film may be formed into a desired shape by vacuum forming or the like before being placed in the mold. This in-mold forming method can combine the sheet or film with the base into the monolithic structure at high productivity, or transfer only the printed section.
Japanese Patent Laid-Open No. 9-263614 discloses an acrylic resin film suitably processed by the above-described in-mold forming method and having excellent printing characteristics. More specifically, it describes that the acrylic resin film with excellent printing characteristics, 80 xcexcm or more in diameter, one/m2 or less in foreign matter concentration and 300 xcexcm or less in thickness, can be produced from the acrylic resin composition containing given quantities of a thermoplastic polymer and rubber, the thermoplastic polymer being produced by polymerizing a given monomer mixture by a given method, and that the acrylic resin film, when printed, can realize excellent printing characteristics, controlling missing prints resulting from fisheyes.
Recently, the printed acrylic resin film surface is required to be matted, and provided with a design or decoration for feeling of high quality, deepness or the like. Such requirements can be satisfied by printing a matted acrylic resin film.
Japanese Patent Laid-Open No. 10-237261 discloses that a matted acrylic resin film wherein the surface gloss is not easy to change can be produced from the acrylic resin composition, described in Japanese Patent Laid-Open No. 9-263614, by incorporating therein a rubber-containing polymer with particle size controlled within a specific range and matting agent, e.g., inorganic powder, organic, crosslinked powder or straight-chain polymer having hydroxyl group.
Japanese Patent Laid-Open No. 10-237261 does not describe missing print in detail, which may occur when a matted acrylic resin film is printed. The inventors of the present invention have printed the matted acrylic resin film prepared in accordance with the method described in the specification to find more than 10 missing prints per unit area (1 m2) of the printed surface. Therefore, it has still room for improvement in printing characteristics, although excellent in matting characteristics.
In general, the missing prints, when massively occur on the printed acrylic resin film, deteriorate its decorations and outer appearances, and also yield.
It is an object of the present invention to provide an acrylic resin film having excellent matted outer appearances and good printing characteristics, e.g., little suffering missing prints when printed. It is another object of the present invention to provide a method of producing the above acrylic resin film. It is still another object of the present invention to provide a laminate coated with the above film.
The inventors of the present invention have found, after having extensively studied to solve the above problems, that the acrylic resin film exhibits very good effects, when its surface gloss on the front side is different from that on the back side, and the difference in gloss is in a specific range, reaching the present invention.
The present invention provides the acrylic resin film having a differential 60xc2x0 surface gloss of 5% or more between the front and back sides, and thickness of 300 xcexcm or less.
The present invention also provides a method of producing the above-described acrylic resin film, where a molten acrylic resin composition is extruded, and then rolled between a mirror-ground roll and rubber or embossed roll into the film.
The present invention also provides a laminate of an acrylic resin film, with the film side having a higher 60xc2x0 surface gloss coming into contact with the base.